1. Field of the Invention
The present invention relates to an image taking apparatus, and more particularly to an image taking apparatus which can maintain excellent image quality by appropriately making shading correction even if a light source is changed.
2. Description of the Related Art
Generally, in an image taking apparatus such as a digital camera having a lens, shading occurs in which the light quantity decreases nearer to the periphery of photographed image, caused by the lens and the device. Conventionally, a method for correcting the shading has been proposed.
For example, Japanese Patent Application Laid-Open No. 8-279902 disclosed that a shading corrected video signal is obtained by making the arithmetical operation between the shading correction factor preset based on the angle of incidence for a light flux incident upon each photocell and a digital video signal. Japanese Patent Application Laid-Open No. 2005-277618 disclosed that the shading correction is made by adjustment according to the shading factor based on the distance from the correction center of an image. Japanese Patent No. 2805100 disclosed that a shading correction signal is formed based on the shading correction data obtained by integrating the level data in the horizontal direction, and the shading correction data obtained by integrating the level data in the vertical direction, and the shading correction is automatically made based on the formed shading correction signal at the time of actual photographing. Japanese Patent Application Laid-Open No. 2000-41179 disclosed that the shading correction is made in accordance with a photographic scene by selecting the shading correction data according to the f-number, zoom position and kind of lens.